Electron discharge device



Jurie 9, 1936. F, HERRIGER 2,043,659

ELECTRON DISCHARGE DEVICE I Filed July 11, 1954 INVENTOR FEL'X HERRIGERATTORN EY Patented June 9, 1936 UNITED STATES PATENT OFFICE ELECTRONDISCHARGE DEVICE tion of Germany Application July 11, 1934, Serial No.734,564 In Germany July 21, 1933 8 Claims.

My invention relates to an electron discharge tube of the thermionictype for the production of very short waves.

It is well known that for the production of extremely short continuouswaves an electron discharge tube may be connected in what is known asthe Barkhausen-Kurz circuit. In such an arrangement a high positivevoltage is impressed upon the grid of a triode, while upon the anode 10(also called the retarding-field electrode) there is impressed anegative or a very small positive potential. Diodes can also be employedfor the production of oscillations of this kind. In each of theseexamples, the periodic building up and collapse or decay of thespace-charge has been found to be important for the production of thewaves.

The useful energy or output that is attainable is limited by the maximumgrid loss energy that may be carried ofi. Hence, for the. generation ofcomparatively large outputs it is necessary to connect several tubes inparallel. One difliculty in present devices is that the connections orleads used to unite the several systems result in coupling efiects ofdifferent kinds dependent upon the frequency that is generated.

Another diiiieulty is that in the case of paralleling more than twotubes, proper balance is difficult to obtain.

The object of my invention is to provide an electron discharge deviceparticularly suitable for ultra-short waves and having a comparativelyhigh output in comparison to present tubes used for generatingultra-short waves. More specifically it is an object of my invention toprovide an electron discharge device which is in effect a plurality ofelectron discharge devices which may be connected in parallel to delivera high output at ultra-high frequencies but which is free of thediificulties usually encountered in parallel connections of electrondischarge devices intended to have a large output.

According to my invention symmetric parallel conditions are obtained byconnecting in parallel a plurality of diodes instead of .triodes. Withinthe envelope of the tube I provide an even number of aperturedelectrodes (grids), which are radially disposed and between each pair ofgrids, an apertured, ribbon or filamentary emission surface ispositioned. The electron emission surface in this arrangement serves atthe same time as a cathode and as a retarding-field electrode for twogrids, the nth grid in each case being united with the n+2nd grid withthe result that adja- 55 cent grids oscillate in phase opposition orpushpull fashion. In this manner it is possible to shift the reversalpoint of electrons periodically to alternate sides of theelectron-emissive surface, such-shift of the reversing point beingnecessary to produce a periodic-bullding-up and collapse of thespace-charge.

However, it would also be conceivable to use an arrangement in which thegrids are interconnected, while the cathodes oscillate in phaseopposition. In this case, all of the grids would 10 be directlyconnected with one another and they would have no alternating potentialapplied to them, whereas the nth cathode would in each instance beconnected with the n+2nd cathode.

It is important in this connection to have an 5 electron emittingsurface that is as uniformly apertured as possible. According to myinvention, this condition is satisfied by providing a number of hotcathodes of gridor network-construction and connecting them either inparallel or in se- 20 ries, or by using a plate-shaped emitting surface.Where only a few heated cathodes are employed, a homogeneousretarding-field potential is produced by providing between pairs ofheated cathodes, an electrode preferably kept at cathode potential. Thisauxiliary electrode may be apertured or solid.

The novel features which I believe to be characteristic of my inventionare set forth with particularity in the appended claims, but theinvention itself will best be understood by reference to the followingdescription taken in connection with the accompanying drawing in whichFigure 1 is a horizontal cross-section of a tube embodying my invention,Figure 2 is a longitudinal section 35 of the tube shown in Figure 1 withparts removed to make the figure more easily understood. Figure 3 is anenlarged perspective view of a portion of the grid structure.

The cold electrodes l to H2 inclusive, which are 40 grid-like orapertured as best shown in Figure 3, are disposed radially, and consistof parallel strips of sheet material 30 forming a screen, which for thepurpose of preventing a large primary grid current, are so arranged thattheir wide sides are positioned in the direction of flow of theelectrons. The grids I, 3, 5, 1, 9, H are externally welded to wirerings or loops I3, while the grids numbered 2, 4, 6, 8, l0, I2 aresecured 50 to three rings l4.

As shown in Figure 2, in which, for the sake of clarity of illustration,only the grids t and 9 are indicated, between each pair of the grids areinterposed two parallel thermionic or heated cathodes I5 and I6. Betweenthe two cathodes envelope. This is mounted a rod 3| maintained atcathode potential, adjacent cathode I5 a similar rod 32, and adjacentcathode IS a rod 33. These rods serve for improving the distribution ofthe potential, and are secured to the supporting and distributing ringI1. Attached to the distributor ring are all of the cathodes. This ringis supported by the heater supply lead 22. Upon the opposite end of thecathodes is a fine wire spring l8 to which is fastened the molybdenumwire I9 for carrying the current. The fine wire springs are arranged onthe distributor disc 20, which, in turn, is secured on the heavyheater-supply lead 2|. The grid supporter rings 13 are welded onto thesupply lead 23, and the grid supporter rings H onto the supply lead 24.At one end of the glass body are sealed in the press 26 both the cathodeleads 2| and 22 as well as the grid leads 23 and 24. The grid leads onlyare brought out thru the press 21 at the opposite end of the press, whenmounting and assembling the tube, is mounted by the aid of the bushings28 over the grid leads 23 and 24, the slip springs 29 being furtherprovided for the purpose of insuring proper electrical contact.

While I have indicated the preferred embodiments of my invention ofwhich I am now aware and have also indicated only one specificapplication for which my invention may be employed, it will be apparentthat my invention is by no means limited to the exact forms illustratedor the use indicated, but that many variations may be made in theparticular structure used and the purpose for which it is employedwithout departing from the scope of my invention as set forth in theappended claims.

What I claim as new is,

1. An electron discharge tube for ultra-short waves having an envelope,a plurality of apertured cold electrodes disposed within said envelope,a set of rings supporting alternate cold electrodes radially andoutwardly from said rings, and a second set of rings larger in diameterthan the first set and coaxial with the first set and supporting theremaining cold electrodes radially and inwardly from said second set ofrings, and a thermionic cathode interposed between each pair ofjuxtaposed cold electrodes and consisting of filamentary elements lyingin a radial plane.

2. An electron discharge tube for ultra-short waves having an envelope,a plurality of apertured cold electrodes disposed radially within saidenvelope and a thermionic cathode interposed between each pair ofjuxtaposed cold electrodes and consisting of filamentary elements lyingin a plane and alternate cold electrodes being electricallyinterconnected, said cold electrodes consisting of a pluralityofparallel sheet strips forming a screen lying in a radial plane, saidstrips lying in planes perpendicular to the radial plane of the coldelectrodes.

3. An electron discharge tube for ultra-short waves having an envelope,a plurality of apertured cold electrodes disposed radially within saidenvelope, and a thermionic cathode interposed between each pair ofjuxtaposed cold electrodes and consisting of filamentary elements lyingin a plane, auxiliary electrodes positioned between the filamentaryelements comprising said cathode and co-planar therewith, said cathodesbeing electrically connected and alternate cold electrodes beingelectrically connected in parallel.

4. An electron discharge tube for ultra-short waves having an envelope,a plurality of electrodes in said envelope, and comprising alternatecold electrodes and cathodes,each of said cathodes comprisingfilamentary elements lying in a elements lying in a plane and auxiliaryelectrodes mounted between the filamentary elements comprising saidcathodes and co-planar therewith.

6. An electron discharge tube for ultra-short waves having an envelope,a plurality of electrodes in said envelope, comprising alternate coldelectrodes and electron emitting cathodes, each of said cathodescomprising filamentary elements lying in a plane and auxiliaryelectrodes mounted between the filamentary elements comprising each ofsaid cathodes and co-planar therewith.

7. An electron discharge tube for ultra-short waves having an envelope,a plurality of electrodes in said envelope, and comprising electronemitting electrodes disposed in a radial plane and a cold electrodepositioned in each space between adjacent electron emitting electrodesand consisting of a. plurality of parallel sheet strips forming a screenlying in a radial plane, said strips lying in planes perpendicular tothe radial plane of said cold electrode whereby the planes of saidstrips lie parallel to the direction of travel of electrons from saidelectron emitting electrodes.

8. An electron discharge tube for ultra-short waves having an envelope,an inner support and an annular outer support coaxial with andsurrounding said inner support within said envelope, and a plurality ofperforated cold electrodes projecting radially from each of saidsupports toward the other and with the projecting electrodes on eachsupport interleaved with the projecting electrodes on the other supportand an electron emitting electrode disposed in a radial plane betweeneach pair of juxtaposed cold electrodes.

FELIX HERRIGER.

